Deep Freeze is a system-level program that prevents user changes from "taking hold" and reconfiguring or possibly damaging a computer. In CPS, schools should use the CPS enterprise version of Deep Freeze, available free from ITS. If you haven't yet read the Deep Freeze Overview please take a look at that before continuing with this Deep Freeze details page.
Help for your students (and teachers!)
Before your users get on a Deep Freeze frozen computer, they should be briefed about what differences they will experience. Most significant among the possible pitfalls is loss of documents which are saved to desktop or to MyDocuments (if this is not redirected). Some CUIP schools using Deep Freeze have prepared a one-page handout derived from the example linked below, explaining the precautions to save files in an approved way. You would need to edit this not only to put in your school's correct name, but to check which storage options apply to your school. For example, do they have shortcuts to personal home folders on a school fileserver? Do you expect them all to have USB flash drives? In any case, the Thaw Space (usually drive T:\ ) is an option made available by Deep Freeze and should be pointed out to them.
Here is a sample document handed out by a CUIP staff person and the school TechCo. You would of course want to adapt this for your own context.
(Point back to Installation note, as of version 6? or perhaps 5, if the workstation has big C: and D: drives separate, the installer program offers checkboxes for "what Volumes should be frozen?". If you check only C:, that will leave all of D: as essentially a very large Thaw Space though not named such.)
Tech Details for Thaw Space
In some setups (including new Version 6 installations as of the end of the 2008-09 school year), the permissions settings on the Thaw space drive are such that non-privileged users cannot save files directly to the root of the Thaw Space drive. Instead, they can make a new folder, and then within that folder they will have full write permissions, including file saving. The owner-creator of each folder has extensive rights over her\his own folders, but not other users' folders.
If set up this way at your school, teachers should know about it so they can help students who might be stymied when trying to save directly at the root of T:\. If there is already a folder accessible to them they don't need to make a new folder; although the teacher may want to encourage making separate folders named for the individual students (regardless of whether they are using the same generic login).
This scheme of permissions seems to make sense, but more so in a context where users log in differently and thus get protected folders. But in practice, either the students are generally logging in as a shared generic username for a this-computer local login (like "school"), in which case all the folders created under that login, even if named for different actual students, will be open to anyone logging that way who cares to probe the files; or else the school uses personal INSTR or First Class logins for the students, in which case they could be storing documents to the school INSTR fileserver or the first Class personal file storage, and won't have much call to save into the local computer's Thaw Space anyway.
---
When initially requesting to be activated under Deep Freeze, the school (the TechCo) can request a different drive letter be assigned to the Thaw Space. This may be desirable if there is already in place a system of drive mappings that includes use of T:\. You can also request different sizes for the Thaw space.
Deep Freeze
Deep Freeze is a system-level program that prevents user changes from "taking hold" and reconfiguring or possibly damaging a computer. In CPS, schools should use the CPS enterprise version of Deep Freeze, available free from ITS. If you haven't yet read the Deep Freeze Overview please take a look at that before continuing with this Deep Freeze details page.
Help for your students (and teachers!)
Before your users get on a Deep Freeze frozen computer, they should be briefed about what differences they will experience. Most significant among the possible pitfalls is loss of documents which are saved to desktop or to MyDocuments (if this is not redirected). Some CUIP schools using Deep Freeze have prepared a one-page handout derived from the example linked below, explaining the precautions to save files in an approved way. You would need to edit this not only to put in your school's correct name, but to check which storage options apply to your school. For example, do they have shortcuts to personal home folders on a school fileserver? Do you expect them all to have USB flash drives? In any case, the Thaw Space (usually drive T:\ ) is an option made available by Deep Freeze and should be pointed out to them.Here is a sample document handed out by a CUIP staff person and the school TechCo. You would of course want to adapt this for your own context.
DeepFreeze_Saving_Instructions.doc
(Point back to Installation note, as of version 6? or perhaps 5, if the workstation has big C: and D: drives separate, the installer program offers checkboxes for "what Volumes should be frozen?". If you check only C:, that will leave all of D: as essentially a very large Thaw Space though not named such.)
Tech Details for Thaw Space
In some setups (including new Version 6 installations as of the end of the 2008-09 school year), the permissions settings on the Thaw space drive are such that non-privileged users cannot save files directly to the root of the Thaw Space drive. Instead, they can make a new folder, and then within that folder they will have full write permissions, including file saving. The owner-creator of each folder has extensive rights over her\his own folders, but not other users' folders.
If set up this way at your school, teachers should know about it so they can help students who might be stymied when trying to save directly at the root of T:\. If there is already a folder accessible to them they don't need to make a new folder; although the teacher may want to encourage making separate folders named for the individual students (regardless of whether they are using the same generic login).
This scheme of permissions seems to make sense, but more so in a context where users log in differently and thus get protected folders. But in practice, either the students are generally logging in as a shared generic username for a this-computer local login (like "school"), in which case all the folders created under that login, even if named for different actual students, will be open to anyone logging that way who cares to probe the files; or else the school uses personal INSTR or First Class logins for the students, in which case they could be storing documents to the school INSTR fileserver or the first Class personal file storage, and won't have much call to save into the local computer's Thaw Space anyway.
---
When initially requesting to be activated under Deep Freeze, the school (the TechCo) can request a different drive letter be assigned to the Thaw Space. This may be desirable if there is already in place a system of drive mappings that includes use of T:\. You can also request different sizes for the Thaw space.
Other articles on this wiki for Deep Freeze: